Shock mount



June 16, 1953 E. PIETZ SHOCK MOUN 'iK Fil ed March; 12, 1946 awe/whom ERVIN PIETZ Patented June 16, 1953 SHOCK MOUNT ErvinPietz, Cambridge, Mass., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Application March 12, 194 6, SerialNo. 653,906

'This'invention relates to resilientmountings 2Claims. (01.248-353) andmore particularly to a new and improved vibration and shock absorbing mounting.

' In order properly tov support devices for use and yet isolate them from destructive vibrations and shocks as in aircraft, automobiles, and other installations, there have heretofore been employed resilient mountings-including a resilient or yieldablematerial', such as rubber, which were used to dampen the shocks and vibrations other wise transmitted to the device being supported. Inthe proper design of such resilient'mountings a numberof importantfactors must be given increasetthe shock isolating and vibration absorbi'ng characteristics thereof.

Another object. of the present invention :isito' provide a' new and improved shock mount design wherein. thezresilient material is loaded in compressionfor a force applied in any direction.

Stillanother object of the invention is to dispose the metal and resilient parts in such a manher that the rubber, regardless of the magnitude of the force on the mount, will always remain between the metal parts. This prevents the impacting of metal against metal during shock.

- A further object is to use opposed rubber pads slightly'precompressed. This has the desirable efiect of maintaining natural frequencies suf; ficiently high to avoid-resonance with the vibration on ships and, at the same time, provides sufje ficient flexibility to give good shock protection.

Astill further bject is to provide a mount having equal stiffness inall directions. This is important in shipboard service since S hOOkS are applied from any direction. Furthermore, af mount. with substantially equal stifin'esse's in'all directions makes possible adequate control ofnaturalfrequencies.

Another object is to provide a mount which is captive; in other words, the mount edequip ment is prevented from becoming amissile in event of failure ofthe rubber parts.

Q Further objects andadvantages will be appar-j ent from the specification and appended draw ings in which latter, l 7

Fig. 1 is :a vertical sectional elevation of one embodiment of the present invention takenon a line substantially corresponding to line ll of Fig.t2;.

Fig; 2:is a bottom plan view of a mount constructed in accordance with the disclosure of Fig. 1;

Fig. 3 is a top plan view of the outer resilient ring member employed in the embodiment illustrated; and

. Fig. 4 is a top plan view of the inner resilient.

ring member employed in the embodiment illus- V trated.

' Referring to the drawings in detail: a

The. embodiment illustrated'comprises a support enga ing member 10 which may be formed of a single blank as illustrated in Fig. 2 and having a'raised central embossment ll whichhas a concentric opening therein. An inner cup shaped shell l3 and. an outer, cup shaped cover I4, are spaced on opposite sides of the embossed portion I l l of the bracket I0 and are of similar configuration to the portion 1 l., The. inner shell l3 and the outer cover l4 may be. structurally spaced apart by a tubular sleeve I5 through which a tie bolt; it extends and may be secured in place by afastenernut H. The tie bolt It may extend through an instrument support member l8 so as to clamp this member securely to the upper surface of the outer cover [4.

With the arrangement illustrated there is provided a support mount having a pair of annular spaces on opposite sides of the portion ll of member [0, which spaces may be filled by shaped rings of resilient material, such as rubber, which rings preferably have overhanging sides so that they extend substantially down the side of the up-v standing embossment ll of member 10, as is illustrated in detail in Fig. l.

"The resilient material employed may vary in shape and configuration as circumstances require-However optimum results have been found to be obtained by the use of an inner member l9 (Fig. l) which has a tapered central face 2(i' and has a beveled or cham feredouter inclined face 2 l An outerresilient member 22 is similarly formed and may have a similarly tapered central face 23 and an outer beveled face 24. If desired, in orderto provide a softer more resilient mount theremay be provided about the upDQrsurface of the resilient-member 22 an annulus 25 concentric with the center of the tie bolt and providing an additional bulge space for-the resilient material. l I

- Openings- 2'! inthe corners of the plate I 0 may receive bolts or other fastening means to secure the mount to a base or to connect an instrument to the mount.

The horizontal parts of the resilient members I9, 22 resist the vertical forces and are arranged t be slightly compressed when in normal position. The stifinesses of these resilient members are therefore added, thus increasing the natural frequency of vibration. When a shock is applied, however, the instrument support member I8 is displaced relative to the member 10 and onlyone of the resilient members 19, 22 is operative.

Increased shock protection results from the reduced stiffness provided by the single resilient member. r

A particularly novel feature of the invention-is the means used to obtain equalstiffness. all, directions. This requires substantially equal bearing areas on the resilient material in both horizontal and vertical directions which are not attained. with existing; designs. For. example, in Patent No. 1,912,210 granted t Funk-;onMay.30, 1933, the area .of the. insulating bushing: 35 on the sleeve 34 is of limited extent and resultsirnre duced. stiffness. in. adirection perpendicular-to the boltl. unless the .dimensions-iofethe. mount; are made unreasonably large. In my invention utilize thedepending skirt Zia-to provide stifiness in the horizontal direction; Thisskirthaslanlarge diameter and consequently can be made with a horizontal area substantially equal .toothe. area subjected. to the verticaliloads. The equal stiffe ness resulting from such an arrangement is; very advantageous for applicationswhere. equal. naturalv frequencies in all. directions; are. required, such. as in the mounting of; delicate equipment,

aboardship. i.

Whilecaparticulan.embodimentsoi the invention is shown, it will -.be understood, of course, thatlit is not desired to be limited; thereto since 4 rings is loaded in compression for force applied in any direction and substantially equal stifiness in all directions is provided, said separate inner and outer cup-shaped resilient rings each having an annular outer conical surface adjacent its periphery providing bulge space respectively Within said outer shell and within said embossment, and each resilient. ring having ga'; central inner conical surface tapering inwardly of the ring and providing bulge space respectively beneath the upper wall of the outer shell and besaidinner; andouter shells in spaced relationship including a spacing sleeve disposed between and engaging said inner and outer shells and extendmanymodificationsmay be made, audit is, there;

fore, contemplated by the appendedclaims to cover any such modificationsas fall withinthe truespirit a-ndscopeof this invention.

What is claimedisz a 1. resilientmounting comprising a base member having an upstanding central embossment havingacylindrical *si'de" wallportion-and an upper wall portion extending substantially at a right angle to the oylindri'cai-side-wall portion and having a central openingtherethrough; inner and outer shell-s each havinga cylindrical side wall'portion and an upperwal'l portion extending substantially at a right angleto thecylindrieal side wall portion andhaving a central opening, said inner shell being disposed within 'andwithits cylindrical wall portion andupper-wallportion spaced from those of saidcentral embossment of the base member, said outershellbeing disposed without and with its cylindrical wall portion and upper'wa-ll portion spaced from thoseof said central embossment; means-for retaining said inner and outer shells in said spaced rela* tionship, and separate inner-and outencupshaped rings of-resilient'material positioned re spectively between the embossmenir of thebase.

member and thespaced inner-and outer shells,- each of said cup-shapedresilient/rings having innerand outer cylindrical surfaces and innerand outer surfaces extending substantially atright angles to saidcylindricaisuriaces, saidsurav faces of said cup-shaped resilientringsbeingi'n; engagement. respectively with corresponding. .511 faces of the walls of said embossment and shells whereby the resilientzmaterialiofsa dtqlmffih li {o p ing through said central opening of said central embossment, and. securing. means, extending through thealig-ned central; openingsof, said in ner and outer shells. and'..through Said. spacing sleeveandadapted tqsecure said mounttaa S pport'memben 1 1 c 25A resilient mounting. comprising. a. haste. membeu having an upstanding; central, .emhoss; ment having a cylindricalsida wallportion and upper wall portionuextending substantially;- at a right angle tothecylindricalside. no, tion and having a central opening therethrougha inner-and outer shells: each having a cylindrical side wall portion and" anupper wall portion BX:- tending-substantiallyat a. right angle. tothn QYfi'D-rr drical side wall portion andihavingja. central; opening; said inner shell beingv disposed within andwith its cylindricallwall portion and upper wall portionspaced' from those of said; central: embossment ofthe-base membensaid outer-Shell; being disposed withoutiand" with its: cylindrical waliportionand upper wall portion spaced-from those of said central embossment,. means; for 16: taming said innerand outer shells in said spaced,- relationsh-ip, and-separateinner-and outer cupshaped rings of resilient material positioned-respectively' between the embossm'ent of; the; base member and the spaced inner and outer shells; each of said cup-shaped resilient; rings: having; inner and outer cylindrical surfaces; and innerand' outer-surfaces extending substantially; lat right angles te'said cylindrical surfaces; said; surfaces or said oup-shaped resilient'rings: being in engagement respectively with corresponding surfaces; of the walls of said embossment: and shells: whereby the resilient material of said cup-shaped; rings is loaded in compression. for force applied in any direction-and substantially equal stiffness; in all direct-ions isprovided, saidseparate inner am outer cup-shaped resilient rings each having an. annular outer" conical surface adjacent-its periphery providing bulge space respectively within said outer shell and'within said-embossment, and each rv'esilient'- ring having a central? inner c'zo'nical vsurface,tapering inwardly of the ringg andflpr oviding bulge] space. respectively beneath the. upper" wall or, the, outer shell and; be-" neath the upper wall of the said embldssmentlsaidi means for retaining said inner 'andoutershells in spaced, relationship including a. spacing. sleeve; disposedbetween and engaging said inner and.

outer shells and extending throughsaid central opening of said cehtral, embossment, and. securing means eatending through: the, alignedv central ings of said inner 5 through said spacing sleeve and. adapted to secure Number said mount to a support member. 7 2,256,752 ERVIN' PIETZ. 2,271,016 2,352,049 References Cited in the file of this patent 5 2,386,463

UNITED STATES PATENTS 2,399, Number Name Date 2306501 1,728,871 Masury Sept. '17, 1929 1,892,065 Markey Dec. 27, 1932 2,018,860 Lord Oct. 29, 1935 Number 2,022,102 Anibal Nov. 26, 1935 418,781

Name Date Saurer Sept. 23, 1941 Julien Jan. 27, 1942 Weaver June 20, 1944 Hile Oct. 9, 1945 Wells et a1. Apr. 30, 1946 Fyler Aug. 27, 1946 FOREIGN PATENTS Country Date Great Britain Oct. 13, 1934 

